allen



E. B. ALLEN.

TENSION CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED AUG. I6. 1919.

1 ,346, 1 O3 Patented July 13, 1920.

3 SHEETS-SHEET l.

WITNESSES:

E. B. ALLEN.

TENSION CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED AUG. I6. 1919.

Patented July 13, 1920- a SHEETS-SHEET 2.

INVENTOR ATTORNEY WITNESSES:

E. B. ALLEN.

TENSION CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED AUG. 16, 1919.

3 $HEETS-SHEET 3- INVENTOR mfl M ATTORNEY Patented July 13, 1920.

UNITED STATES PATENT OFFICE.

EDWARD B. ALLEN, 0F NEWTOWN, CONNECTICUT, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

TENSION-CONTROLLING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented July 13, 1920.

Original application filed February 16, 1918. Serial No. 217.483. Divided and this application fled August 16, 1919.

T 0 all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Newtown, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Tension- Controlling Mechanisms for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

The present invention, which has been divided out of my copending application Serial No. 217,483, filed February 16, 1918, has for an object to provide an automatic sewing machine, more particularly of the buttonhole type, with improved mechanism which will not automatically and in a positive manner to release the tension at the end of the stitching cycle, preferably after the stitch-forming mechanism has come to rest.

A further object of the invention is to provide an improved mechanism for effecting the restoration of the tension prior to the next stitching operation.

A more general object of the invention is to provide a cam and follower mechanism wherein the cam operates normally to shift the follower away from an initial position, with means whereby the follower may be restored to initial position while the cam is stationary.

A further object of the invention is to provide a cam and follower mechanism wherein the cam normally actuates the follower, with means for moving the follower along the cam to alter the time at which the follower would be actuated by the cam if the motion of the latter alone were depended Still further the invention has for an object to provide a cam actuated mechanism suitable for operating various sewing machine thread-handling devices such as pullofi's, tensions, thread-cutters, and the like, which it may be desirable to operate at different periods of the stitching operation.

To the attainment of the above and other objects, as will hereinafter appear, I have embodied the invention in an automatic buttonhole cutting and stitching machine and have combined with the stitch-forming mechanism and with the usual cutter-shaft which is driven independently of the stitch- Serial No. 317,903.

forming mechanism and performs a single rotation at one stage of the buttonholeroducing c cle, a second auxiliary shaft w 'ch 1s also riven independently of the stitchforming mechanism and is caused to perform in a positive manner the various operations durin another stage of the buttonhole-producing cycle. Preferabl this second auxiliary shaft is controlled t rough an automatic clutch permitting it to rform a single rotation only; the clutch bemg tripped into action preferably by the stop-motion device for the stitch-forming mechanism at the end of the stitching or second stage of the buttonhole-produ cycle so that the second auxiliary shaft wi perform its function or functions only during the third or final stage of the buttonhole-producing cycle.

The second auxiliary shaft is provided, in the present machine, with a cam which acts through a follower and suitable connections to release the tension, trip the thread-cutter and open the work-clamps in a predetermined order and at properly spaced time intervals.

Suitable connections with t1 2 stop mechanism serve to shift the cam-follower pe- "ripherally of the tension-releasing cam to efi'ect the restoration of the tension at the be inning of the next sewing operation,

he gist of the invention, in its broader aspects, is the provision of cam-and-follower mechanism, wherein the cam moves at times to shift the follower, with a follower shifting means which may be operated to move the follower along the cam whereby the time of actuation of the follower is not solely dependent upon movement of the cam.

In the accompanying drawings, Figure 1 is a side elevation of the machine, partly in section. Fig. 2 is a rear elevation of the machine. Fig. 3 is a plan view, partly in section, showing the feed-wheel, the two auxiliary shafts and the mechanism associated therewith. Fig. 4 is a view inelevation of the feed-wheel and the crank mechanism for turning the latter at one stage of the cycle and Fig. 5 is a detail perspective view of said crank mechanism- 6, 7 and 8 are detail perspective views of the clutch-controlling mechanism for the auxiliary shaft shown in Figs. 4am! 5.

9 and 10 illustrate details of the clutch-controlling mechanism in elevation. Fig. 11 is a View of the cam and follower which control the tension-releasing, thread-cutting and clamp-opening operations.

In the particular embodiment of the in vention chosen for the purposes of the present disclosure, the machine frame comprises the hollow rectangular base 1 formed with a bed-plate 2 from the rear end of which rises the hollow standard 3 carrying the usual bracket-arm 4 which terminates in the hollow head 5. Extending within and lengthwise of the base 1 is the main-shaft 6 for the stitch-forming mechanism. This shaft carries a bevel-gear 7 which meshes with a companion gear 8 of equal size fixed to the lower end of the vertical. shaft 9 journaled within the standard 3. The vertical shaft 9 acts through one-to-two speed multiplying bevel-gears 10 to drive the needle-bar actuating shaft 11 which at its forward end is connected to the reciprocating needlebar 12 by means of the usual crank 13 and link 14. The stitch-forming mechanism of the machine may be of any suitable type. In the presentinstance it is constructed substantially in accordance with the disclosure of myPatent No. 1,162,207, of November 30, 1915, and embodies the reciprocating straight needle 15 carried by the needle-bar 12 and the lower curved needle 16 which is sustained in the turret 17.

Mounted beneath the bed-plate 2 on the screw-pin 18 is the well-known feed-wheel 19 which is formed in its under face with a cam-groove, not shown, acting during a partial rotation of the feed-wheel to shift the cam-follower21, Fig. 3, and through the usual connections therewith, to turn the stitch-forming mechanism while stitching.

around the eyelet-end of a buttonhole, At the end of the stitching operation the feedwheel is given a further turning movement to complete its single rotation and at this time acts to turn the stitch-forming mechanism back to initial position. The cam-fol lower 21 is sustained by a lever-arm 22 fixed at one end to the vertical fulcrum-shaft 23 and at its opposite end connected by means of the link 24 to the bellcrank-lever 25 which carries the usual toothed sector-gear 25 meshing with a pinion 25", Fig. 1, on the turret 17-. The vertical fulcrum-shaft 23 carries a crank-arm 26 which is connected by means of a link 27 to a bellcrank-lever 28 formed with the toothed sector-gear 29 meshing with the pinion 30 connected to the bushing 31 from which depends the guide-arm 32 havinga channelway entered by a stud 33 on the needle bar, all as more fully de scribed in my said Patent No. 1,162,207.

The bnttonhole cutting mechanism of the inachine is preferably constructed in substantial accordance with the disclosure of my Patent No. 1,048,786, of December 31, 1912, and comprises the usual upper and lower cutter-levers 34 and 35 which are advanced and closed to cut the buttonhole-slit in stitching position by means of the usual connections with the cutter-closing cams 36, 36 and the cutter-advancing and retracting cam 37, all carried by the cutter-shaft 38 which is driven independently of the stitch forming mechanism from a constantly running pulley 39 through the well known automatic single-rotation clutch mechanism 40 fully disclosed in my said Patent No. 1,048,786. WVhen the cutter-shaft controlling clutch is tripped into action during the first stage of a buttonhole-producing cycle the constantly running driving pulley imparts a single complete revolution to the cutter-shaft, as is well understood.

The work-holder of the present machine is constructed substantially inaccordance with the disclosure of my copen'ding application Serial No. 180,737, filed July 16, 1917, and comprises upper and lower work-clamping elements 41 and 42, of which the upper are carried at the forward ends of the clamp- 7 mechanism is controlled by means of a suit able stop-motion device preferably such as disclosed in my said Patent No. 1,048,786. A stop-motion device of this type embodies a tilting starting and stopping lever which is fixed to a fulcrum-pin 46 journaled in the bearing lugs 47. The. lever 45 is ur ed to stopping position by the spring 48 and is held in running position, Figs. 1 and 2, by means of the latch 49, the upper'extremity of which engages over a wear plate 50 on the arm 51 fixed to and extending forwardly from the fulcrum-pin 46. The arm 51 carries a cam-roll 52 at its free end which is depressed by a cam 53 on the cutter-shaft 38 to start the stitch-forming mechanism during the latter part of the single rotation of the cutter-shaft. At the completion of the stitching operation a tripping point 54 on the feed-wheel acts'through a lever 55 to displace the latch 49 laterally and release the lever-arm 51 thereby permitting the stop lever 45 to spring to stopping position.

As is well understood by those skilled in the art, stop-motions of the present type embody a downwardly spring-pressed slideblock 56 which is mounted upon the stoplever 45 and is formed with a tooth 57 which snaps into position over the peripheral sur face 58 of the clutch-ring 59 when the stoplever swings to stopping position. Further turning movement of the main-shaft causes the slide-block 56 to be lifted as the outwardly inclined cam-portion 6 0 of the clutchclutchming, as the abrupt shoulder 62 formin one side wall of said notch strikes the si e face of the tooth 57 and arrests the motion of the main-shaft. This well known upward and downward movement of the slideblock 56 is utilized in the present machine for a purpose to be hereinafter described.

The present machine embodies, in combination with the foregoing features of construction. a second auxiliary shaft 63 which is journaled within and transversely of the bed 1 in the bearings 64 and 65, Fig. 3, and, in the present instance, is utilized to release the tension subsequent to stitching. This shaft is normally stationary during the stitching operation and is caused to perform preferably a single revolution only during the third or last stage of the buttonhole-producing cycle. Mounted to turn freely upon an outboard projection of the shaft 63 is the constantly rotating driving disk 66 of an automatic one-revolution clutch device. ()ne side face of the disk 66 is recessed to form a peripheral flange 67 into which is let a series of peripherally spaced and in- Wardly directed driving teeth 68. The driving disk 66 is further formed with a hub 69 integral with which is a gear-wheel 7O meshing with a pinion 71 fixed to the wellknown belt-wheel 39 which turns freely upon the first auxiliary or cutter-shaft 38. The arrangement of the auxiliary shafts 38 and 63 in parallelism transversely of the machine bed and the gear connected drivin disks concentric therewith are features 0 86 construction which make for a simple, compact and efficient auxiliary mechanism adapted to be driven from a single beltwheel at the side of the machine and which may be utilized to perform an or all of the 40 various operations before an after stitch- T ixed to the second auxiliary shaft 63 ad- 'acent the driving disk 66 is a driven disk 2 formed with a radial slideway 73 in which is fitted a slide-block 74 having at one side a clutch-tooth 75 which projects laterally into the recessed portion of the driving disk. At its opposite side the slideblock.7 4 isformed with a stopping tooth 76 which projects throu h the slot 77 in the face of the driven dis 72 remote from the driving disk. A spring 78, Fi 6, mounted on the disk 72 and having its ree end bearing against the notched inner end of the clutch-tooth 75 is utilized to urge the slideblock 74 outwardly, thereby projecting the clutch-tooth 75 to a position wherein it will be struck by one of the driving teeth 68, thus coupling the shaft 63 to the source of power. Fulcrumed on the screw-pin 7 9 is a clutchcontrolling bellcrank-lever having a depending arm 80 which at its lower extremity carries an abutment block 81 having an inclined cam face 82, a detaining shoulder 83 and a stop-shoulder 84. Pivoted to the arm passes it.

at 85 is a spring-pr lower extremity .of which is spaced In the normal flopping s 1 eparts thus described, the block 74 is at its extreme inner position with the ehflch- 89 tooth 75 withdrawn from H with the clutch-teeth 68 of the drivi disk 66.

The shifting of the clutch-eontm .belL- A e it a.

crank-lever, by means presently scribed, so as to move the arm 80 awayufma i i the adjacent face of the driving diskfifi, flieengages the stop-shoulder 84 and d shoulder 83 from the stopping tooth'llfi o the slide-block 74, thus 'tting the to move outwardly un er the action Obits spring 78 to introduce the clutch-toetha'lt'i into engagement with one of the driving teeth 68. As the driven disk 72 .nearathe completion of a single revolution; the j clutch-controlling bellcrank-levor has been 5 returned to initial position by the action of both the spring 88 and the morepoiitive action of the inclined face-B9 of as namrib 90 upon the bent extremity 91 eral arm 92 secured to the lower. end

clutch-controlling lever-arm 80, ing the cam face 82 of the abutment block 81 into the path of movement offlieido ping tooth 76 by means of which the.

-waabornthe stop-shoulder 84. The othemarmfii' afthn block 74 is thrust inwardly to disengage its i clutch-tooth 75 from the driving teeth 68. As the stopping tooth 76 arrivesrdtinitial position, it engages the stopmhouldet 84 and is prevented from rebounding by the extremity of the latch 86 which snaps into me operative osition as the stopping tooth76 y the means thus desenibed, the second auxiliary shaft 63 isinsnreda single complete revolution for each clutch-releasing actuation of the contnollingbellcmnk It lever 80, 87.

The second auxiliary shaft 63 is formed between its ends with a bellerank 8 whiai operates through the pitman 9:4, as described in the parent application, tu qui ckly .120

restore the feed-wheel to initialposxtmn during the final stitch of the utt0lfh0lB producin cycle.

It wil be noted that in the normally stationary lposition of the second m 1 V i 1 shaft 63, g. 4, the crank93-is above its rearward dead-center s- In this figure the stop-motion lever 46 he it been tripped and the main-shaft6his yet to turn a part of a revolutiomto first ele- .18. I

.tonhole producing cycle.

vate the stopping tooth 57 and then permit it to snap into the stop-notch 61 of the clutch-ring 59.

Pivoted to the'forwardly extending arm of the lever 96 is a spring-pressed latch 98, Figs. .3 and 8, the extremity of which is adapted to snap under the lateral arm 87 of the bellcrank clutch-controlling lever when the slide-block 56' is lifted by the eccentric surface portion 6'.) of the clutch-ring When the stoppingtooth 57 snaps into the stop-notch 61, the slide-block 56, in falling, acts through the link 95, lever 96 and latch 98 to lift the arm 87 and thereby-retract the depending arm of the bellcrank clutchcontrolling lever and effect the coupling of the auxiliary shaft 63 to the driving disk 66 for a single revolution.

' Pivoted to the frame at 99 is an upstandinglever 100the upper free end of which is yieldingly held against a stop-screw 101 by the action of the spring 88 which is connected at its lower end to a lateral arm 102 of said lever. The lever 100 carries a laterally projecting cam-block 103 having an inclined face 101 which lies in the path of downward movement of the crank-arm 105 and is defiected to one side as the crankarm passes it during the first part of its single revolution, as shown in Figs. 2 and 5. When the lever 100 is deflected, its upper end strikes the latch 98 and disengagesit from the arm 87 of the bellcrank clutch-controlling lever, thereby allowing said lever to immediately return to clutch-disengaging position under the action of the spring 88 or under the more positive action of the cam surface 89 ofthe clutch-wheel 72 upon the bent extremity 91 of the lateral arm 92 fixed to said clutch-controlling lever.

The second auxiliaryshaft 63, with which the present machine has been provided, may be utilized in the performance of various operations during the final stage of a but- For example, the shaft 63 has, in the present instance,

7 been provided with a cam-member 106 in the form of'a pair of spaced disks of similar shape between which is guided thelower end of a lifting bar 107 the upper end of which is pivot-ally connected to the rearward end of the tension releasing lever 108 fulcrumed to the bracket-arm 41 at 109. At its downturned forward end the tension-releasing lever is formed with a lateral recess 110 affording an inclined cam-wall serving when moved downwardly to shift the usual tension-releasing pin 111 inwardly to separate the spring-pressed disks of the tension device 112 for the needle-thread Projecting rearwardly from the lifting bar 107, intermediate the ends of the latter,

is an arm 113 having'at its free end a vertical slot 1141 loosely entered by a screw-pin 115 which is threaded into the lower extremity of the hand-lever 116-pivotally se cured to a boss 117 formed at the upper extremity of the stop-motion lever 45. The. inner end'of the screw-pin 115 projects some distance laterallyof the hand-lever 116-and is yieldingly held in engagement with the stop-motion lever 45, Fig. 3, by means of the spring 118 which is coiled about the boss 117and one end of which is hooked about the'hand-lever 116, Figs. 1 and 2, and tends to pull the upper end of said hand-lever forwardly. The lifting bar 107 screwed to the bed 1. The upwardly and inwardly extending forward extremity 12-1 of the lever-arm 121 overhangs the bed 1 in a position directly beneath the rearward extremity of the latch-lever l25-which locks the work-clamps in closed position. A lever 125 is adjustably fixed to the leverarm 121 by means of the pivot-screw 126 andthe screw 127 which enters 'a slot-125' in the forward extremity of said lever 125 and is threaded into the leverar1n 121. EX tendi? )wardly and in'wardly from the lever into overhanging relation with the bed 1 is an arm 128 which is positioned under the tail of the latch-lever 129 for the AMV thread-cutter rod 130,.as described'iirthe parent application.

7 The rear-wardly extending arm of the lever 125 is adapted to be depressed to elevate the cutter and work-clamp tripping extension 1124:, 128, by means of the lever 129 which is pivoted to the standard 3 at130 and the laterally bent rearward arm 131 of which enters the horizontal slot 132, Fig. 1, in the lifting bar107. The-two arms of the lever 129 are relatively adjustable, one of them being'formed with slot 133 which isentered by screw13et threaded into the other. lhe foregoin parts are soadjusted that when the lifting bar 107 is elevated 't first acts to release the tension, second to trip the thread-cutter and'lastly'to open the workclamps. To secure the proper spacing of these operations in point of time, the cam 106 is formed with a tension releasing rise 135, Fig. 11, which merges into a cutter tripping rise 136 the latter being followed by a dwell 137. which merges into the clampopening rise 138. Following the clampopening rise is a depression 139 which permits the cutterand clamp -opening extensions 124 and 128 to drop sufficiently to insure that the work-clamps may be closed and the cutter reset, but not enough to restore the tension on the needle-thread. F 01- lowing the depression 139 is a long concentric portion or dwell 140 extendingv substantially three-fourths of the distance around the cam and terminating in'an abrupt declivity 141. I

Prior to the starting of the machine, the cam-follower lug 119 rests upon the end of the concentric portion or dwell 140 of the cam, as shown in full lines in Fig. 11. When the stop-lei'er 45 is tilted to starting position .by the action of the usual cam 53 on the cutter-shaft, the lower end of the lifting bar 107 is shifted forwardly, or periphcry of the cam 106 by the action' of the screw-pin 115 carried by the stop-motion lever, and the followen-lug 119 drops over the declivity 141 and moves substantially radially of the cam 106 to the position shown in dotted lines in Figi'll; the cam 106 thus permitting the spring 142 to effect the downward motion of the ifting bar 107 and the consequent restoration of said bar 107 and the follower 119 to initial position, thereby effecting r-ntoration of the thread-tension as the notch 110 of the lever 108 is brought into register with the tension-releasing pin 111.

In the operation of the present: machine which embodies the invention in its preferred form, the work is placed in position under the raised clamping feet and. the machine is started by the usual treadlc-device.

not shown, which trips the cutter-shaft into action. During the single revolution of the cutter-shaft, the work-clamps are closed, the buttonhole-slit is cut and spread and the stop-lever 45 is tilted to running position, Fig. 1, by the action of the cam 53 on the cam-roll 52 at the free end of the leverarm 51; the latch 49 snapping over the lever-arm 51 and holding the stop-motion lever in running position. The tension on the needle-thread is restored when the cam-follower lug 119 is pushed over the declivity 141 by the tilting of the stop-motion lever.

As the stitching progresses, the feed-wheel 19 receives a relatively slow step-by-step turning motion through the usual gear connections with the star-wheel 143, Fig. 1, with which meshes the diametrically opposed pins 144 carried by the lower end of the vertical shaft 9. In stitching around the eyelet-end of the buttonhole, the stitchsnhscquent to the stitching operating,

stop motion therefor, a tension-defied The upward movement of the a 56 carriediby the stop metion lem mgd, the latch extremity of the'leven lateral arm 87 of the bellofenk trolling lever for the secondi-auxiliaiymfi l t 63. As the stoppingtooth'ii'f-drops notch 61 of the cluaeh ringafifi to stitch-forming mechanism, the'dotm movingslide-block56 retraetsthe arm of'the bellcrank-levemjthnsftrip the second auxiliaryshaft fili ntq to perform its singlerevolution din" 1% the tension is released,-the --threaidwia tripped, and the work-clampmare The feed-wheel is also rap dlyirwg'il'im initial positionwithoutnmse wshoQk iri'fle manner described in the While I havedisql' embodied in a buttonholoifivw'ui'ghmriifi of a particular type, it that the invention' in manyflif itsw isi well adapted for "use in automatic sewing machines haf mined aaisles ofeperation as: in m ines generally. 5 ,1 i a Iaving thus set forth thenatnre of thg invention, what I claim herein ii -1 45-; 1. In an automatic sewing combination, stitch formingmec ,1); stop-motion therefor-fa tensionedovicef'forefi the sewing thread, an auxiliary shaft no! mally stationaryfiurin the tion and performing ut a m ans connectedto said shafi' for tlu trnsion (lGVICB; I a a r. in an automatic sewln' g; machine, a |l:\l l()ll, stitch forming-mechani m the sewing thread, an auxiliarygsh ifiinflr mally stationary during the stitehingem'ifii tion and performingbut a singlhetjition, subsequent to the stitching operati means; connected to said shaft for openingl tension-device and means connected with :thelg stop-motion and cooperating fwith theauxiliary shaft while said shaft is stationing to automatically close the tension m when the stitch forming mechanism f started. 5 3,1; 3. In an automatic sewing machine, forming mechanism, a stop-motion thenefat, p a tension device, a tension-controllingrzca'uhx 1185, a cam-follower connected to saidtensum e: vice, means for turning said cam to release an the tension subsequent to the ditching oration, and means for shifti said follower peripherally of saidcani while the latter stationary to e'fi'ect the of the tension at the begi e hemera stitching operation. Q; 4

4. In an automatic sewing machine, forming mechanism, a stop-motion therefor, a tension device, a tension-controll' seam, a cam-follower connected to said 'de- I.

vice, means Vfor'turning said cam to release the tension subsequent to the stitching operation, and means connected to said stopmotion for shiftingsaid cam-follower peripherally'of said'cam While the latter is stationary to effect therestorationwof the tension at the beginning of the next stitchlng operation.

V 5. In anautomatic sewing machine, stitehforming inecl'ianism, a stop-motionitherefor;

a tension device, a tension-controlling cam having a tension-releasing cam-rise and a declivity,- a cam-follower connected to said tension device, means tor turning said cam to release the. tension subsequent to the stitching operation, and means connected to saidstop-motion for pushing said camfol-:

lower over the declivity-of said tension-con trolling. cam While the latter is stationary to efiect the restoration of the tension prior to the next stitching operation;

6. In a sewing machine, an actuated elementya cam, and a cam-follower connected to said actuated element and adapted to, be I 1 acted. upon by said cam, and means; indeot the thread-engaging device time. v

8. In a sewing machlne, in combination,

' stitch-forming mechanism, a thread-engage, 111g dev1ce,,an actuating cam, a cam-follower.

eonneeted to said-thread-engaging device,

means for turning said CZIIIl'fiO control the 40 ction of said thread-engaging device, and means for shifting said cam-follower p ripherally of thecam over an active p012. tion of the-latter to effect 'the' restoration to initial po 45 sition.. V v i 1 V i Intestimony whereof, Ihave signedfmyname to this specification.

ED ARD B. ALLEN] 

